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If you have a functional Corona 4 circa 1930, I would like to get some comparison photos. I have a 1930 Corona 4 with carriage and ribbon vibrator issues. My Corona appears to have bent parts / parts out of place, but it's hard to tell without a functional machine for comparison. See picture below. I am most interested in the areas highlighted with arrows.
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Good news - I found comparison photos at Typewriter Database and was able to make the fix. The Corona Four is now typing.
Typewriter Database is great. As a member of TWDB (which is free), I have access to the documents library which includes parts and service manuals. I am going to make a point of uploading detail photos and "under machine" photos when I create new galleries at TWDB.